A magnetic component that includes: a magnetic core made of a soft magnetic material such as iron, iron alloy, or oxide such as ferrite; and a coil disposed on the magnetic core, is used in various fields. Specific examples may be an in-vehicle component that is mounted on a vehicle such as a hybrid vehicle or an electric vehicle, a motor, a transformer, a reactor, a choke coil and the like that are used as power supply circuit components of various electric devices. The magnetic core includes a lamination product made up of a plurality of thin electromagnetic steel sheets being stacked, and a powder magnetic core. The powder magnetic core is obtained by packing powder of the soft magnetic material noted above (hereinafter referred to as the soft magnetic powder) into a mold assembly to be molded, and subjecting the obtained powder mold product to heat treatment for removing strain.
In the case where the magnetic component is used in the alternating magnetic field, energy loss that is referred to as iron loss (approximately the sum of hysteresis loss and eddy-current loss) occurs at the magnetic core. The eddy-current loss is proportional to the square of the operating frequency. Accordingly, when the magnetic component is used at high frequencies of several kHz or more, the iron loss becomes significant. In such a case where the operating frequency is high, use of coated particles in which an insulating layer is provided to the outer circumference of each of soft magnetic metal particles made of iron or iron alloy (for example, see Patent Literature 1) can effectively reduce the eddy-current loss, and consequently, the iron loss.
In manufacturing the powder mold product, for example as disclosed in Patent Literature 1, a lubricant is applied to a mold assembly by spraying or with a brush. Thus, friction between the mold assembly and the powder mold product is reduced, whereby powder moldability is enhanced. In the case where the powder mold product is molded using soft magnetic powder made of coated particles, use of a lubricant in this manner can prevent the insulating layer from being damaged by sliding contact between the coated particles and the mold assembly or among the particles. Thus, a powder mold product having an excellent insulating characteristic can be obtained. Use of the powder mold product with such an excellent insulating characteristic can reduce the eddy-current loss, and eventually iron loss, of the powder magnetic core.